"Because of wind variability, the energy density at a potential site - commonly described as its capacity factor - is generally in the range of 20-40 per cent. " https://www.ga.gov.au/scientific-topics/energy/resources/other-renewable-energy-resources/wind-energy#:~:text=Because%20of%20wind%20variability%2C%20the,of%2020%2D40%20per%20cent.
